Experimental Investigation of Retrofitted Extended End-Plate Connections

2013 ◽  
Vol 284-287 ◽  
pp. 1330-1333
Author(s):  
Poi Ngian Shek ◽  
M.Md. Tahir ◽  
Cher Siang Tan ◽  
Arizu Sulaiman

A series of retrofitted extended end-plate connections have been tested experimentally and evaluated using the component method specified in Eurocode 3. The component method decomposed the end-plate connection into several components, including the tension zone, compression zone, vertical and horizontal shear zone that occurred at the bolt, end-plate, beam and column. Based on the theoretical model, the moment resistance and the initial stiffness of a connection can be predicted. Four experimental tests on the retrofitted extended end-plate connections have been conducted to verify the proposed design method. From the experiment tests, all moment resistance of the connections showed good agreement with theoretical predictions, which establish a reliable foundation to predict the moment resistance of the retrofitted end-plate connection. All initial stiffnesses calculated from theoretical predictions do not represent the actual behaviour of tested connection. All tested connections can be classified as partial strength based on EC 3: Part 1.8, in condition the welding capacity is at least 50% higher than the capacity calculated from the component method.

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Boon Cheik Tan ◽  
Poi Ngian Shek ◽  
Mahmood Md Tahir ◽  
Ker Shin Mu

This paper presents an analytical study on flush end-plate (FEP) and extended end-plate (EEP) connections connected to cruciform column section using component method. The objective of this study is to predict the moment resistance and initial stiffness of FEP and EEP connections on cruciform column section. A series of FEP and EEP connections are tested in laboratory. The connection tests consist of four FEP and four EEP specimens with different configuration. Component method outlined in the publication of Steel Construction Institute and British Constructional Steelwork Association are based on BS5950 and Eurocode 3 (EC3) are used to predict the moment resistance and initial stiffness of the tested specimens. The experimental results are then used to validate the analytical predictions. As compare to the experimental results, all moment resistance of the connections coincide well with analytical predictions. Analytical prediction for initial stiffness using EC3 does not show good agreement with the experimental results. This study shows that the component method can be used to predict the moment resistance of FEP and EEP connections on cruciform column section. Further study need to be carried out for initial stiffness to obtain accurate analytical representation.


2013 ◽  
Vol 321-324 ◽  
pp. 1766-1769
Author(s):  
Jian Li Zhao

Extend end-plat bolted connections are widely used in steel frames. The rotational stiffness has great influence on steel frame stiffness and deformation. The decrease of the frame lateral stiffness, due to connection rotational deformability, leads to the increase of the period of vibration and the frame sensitivity to second-order effects. This thesis divides the end plate into several parts equivalent to different Timoshenkos beams to determine their contribution to rotational stiffness of the connection. Then stiffness of all parts and bolts is given, and then the component method is used to calculate rotational initial stiffness of extended end-plate connections. Comparisons with results of ANSYS and related tests show that the proposed equations have excellent precision. And the calculating process is simple and easily applicable in practice.


2011 ◽  
Vol 243-249 ◽  
pp. 942-947 ◽  
Author(s):  
Wei Zhao ◽  
Qian Liu

End plate stiffener failures occure in a number of tests in recent years. And no relevant rules are given in design codes for steel structures. A design method for angles and thickness of stiffeners in extended end plate connecionts is derived by requiring the eqaul distribution of tensile force among bolts inside and outside of beam flange. And a balance between the force transmitted by the stiffener and by the beam flange is considered too. Comparisons with results of ANSYS show that the stiffeners designed by the proposed method in this paper are able to change the extended portion of endplates from one side clamped to 2 panels fixed on two adjacent sides. Simple formulas for calculating rotational rigidities of the connections with and/or without stiffeners were also proposed with component method, in which the end-plate stiffness, column flange stiffness and bolt stiffness are inclueded. Comparisons with results of ANSYS show that the proposed equations have good precision and can be applied to pratical engineering.


2010 ◽  
Vol 163-167 ◽  
pp. 591-595
Author(s):  
Jing Feng Wang ◽  
Xin Yi Chen ◽  
Lin Hai Han

This paper studies structural behaviour of the blind bolted connections to concrete-filled steel tubular columns by a serial of experimental programs, which conducted involving eight sub-assemblages of cruciform beam-to-column joints subjected to monotonic loading and cyclic loading. The moment-rotation hysteretic relationships and failure models of the end plate connections have been measured and analyzed. A simplified analysis model for the blind bolted connections is proposed based on the component method. It is concluded that the blind bolted end plate connection has reasonable strength and stiffness, whilst the rotation capacity of the connection satisfies the ductility requirements for earthquake-resistance in most aseismic regions. This typed joint has excellent seismic performance, so it can be used in the moment-resisting composite frame.


2013 ◽  
Vol 12 (2) ◽  
pp. 251-258
Author(s):  
Krzysztof Ostrowski ◽  
Jan Łaguna ◽  
Aleksander Kozłowski

End-plate connections are very often used is steelwork, as tension and bending connections. As a result of deflection of end plate, additional forces, known as prying forces arise and consequently increase stresses in bolts. Eurocode 1993-1-8 do not distinguish end-plate connections prestressed by high strength bolts from non-prestressed. The aim of the paper is to perform the comparison of previous analytical models and code regulations for coefficient of prying forces to the experimental tests and modelling by finite element method. Results of the analysis show that the behaviour of prestressed connection is essentially different with comparison to non-prestressed.


2019 ◽  
Vol 29 ◽  
pp. 02008
Author(s):  
Dominiq Jakab ◽  
Aurel Stratan ◽  
Dan Dubina

During the European research project entitled EQUALJOINTS (European pre-Qualified steel JOINTS) [1], which recently concluded, the matter of providing a set of pre-qualification procedures for moment resisting beam-to-column connections which are currently used in Europe has been addressed. During the experimental campaign 24 specimens with bolted extended end-plate connections with haunches were tested. The current paper presents the numerical model which has been developed such that numerical testing may be performed to further investigate specific details. In what concerns the material, an isotropic material model has been calibrated and used based on tensile tests of coupons extracted from the specimens to model the actual plastic behaviour. Moreover, the imperfections of the beam have been taken into account using a bucking analysis to model as accurate as possible the specimens tested. The interaction between parts has been modelled using contacts with different interaction laws. The model used for the bolt has been calibrated such that the preloading and failure replicate the behaviour of the actual bolts used in the experiments.


2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Giusy Terracciano ◽  
Gaetano Della Corte ◽  
Gianmaria Di Lorenzo ◽  
Raffaele Landolfo

Predicting the response of beam-to-column joints is essential to evaluate the response of moment frames. The well-known component method is based on a mechanical modelling of the joint, through joint subdivision into more elementary components subsequently reassembled together to obtain the whole joint characteristics. Significant advantages of the component method are the following: (i) the mechanics-based modelling approach; (ii) the easier general characteristics of components. However, the method is commonly perceived by practicing engineers as being too laborious for practical applications. Within this context, this paper summarizes the results of a theoretical study aiming to develop simplified analysis tools for bolted end-plate beam-to-column joints, based on the Eurocode 3 component method. The accuracy of the component method was first evaluated, by comparing theoretical predictions of the plastic resistance and initial stiffness with corresponding experimental data collected from the available literature. Subsequently, design/analysis charts were developed through a parametric application of the component method by means of automatic calculation tools. They are easy and quick tools to be used in the first phases of the design process, in order to identify joint configurations and geometrical properties satisfying specified joint structural performances. The parametric analysis allowed also identifying further simplified analytical tools, in the form of nondimensional equations for predicting quickly the joint structural properties. With reference to selected geometries, the approximate equations were verified to provide sufficiently accurate predictions of both the stiffness and the resistance of the examined beam-to-column joints.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Rongqian Yang ◽  
Xuejun Zhou

In order to study the mechanical behavior of bolted beam-column connections, the accuracy and applicability of the finite element model were firstly validated according to the published experiments on end-plate connections using ABAQUS. Then, in order to discuss the mechanical behavior of connections, three semirigid connections which are convenient for prefabricated construction, including top-and-seat angle connections with web and ear plate, extended end-plate connection, and T-stub connection, were examined using numerical simulation analysis to study and compare their capacity, hysteretic behavior, ductility, and degradation characteristics in detail. The results showed that the finite element models that were built could effectively simulate the load bearing behavior of bolted connections under both single-direction loading and cyclic loading. The three connections showed good load bearing capacity. The connectors significantly affected the energy dissipation capacity under load. The extended end-plate connection demonstrated the best performance in both mechanical behavior and manufacture and installation, so it would therefore be the preferred option.


1995 ◽  
Vol 22 (4) ◽  
pp. 745-754 ◽  
Author(s):  
T. Ramadan ◽  
A. Ghobarah

Current seismic provisions require that shear links in eccentrically braced frames be fully welded to the column flanges at the link-column joint. Since field welding may have its disadvantages, the use of bolted extended end-plate connection is examined. An experimental program is conducted to assess the response of extended end-plate connections of link-column joints in eccentrically braced frames. Six link-column joint specimens are tested using a cyclic load that represents the severe load reversals that the frame may be subjected to during strong earthquakes. The specimens are selected on the basis of different connection designs. Measurements of forces, strains, and displacements are made. Interaction curves relating the shear force and moment acting on links with semirigid connections are developed. The slip tendency and energy dissipation capacity of the different specimens are compared. On the basis of the test results, a design procedure is developed for the bolted extended end-plate link-column connection. It is concluded that bolted extended end-plate connections can be used for link-column joints of eccentrically braced frames. In properly designed connections bolt slippage was not measured even at high shear forces that are characteristic of link-column joint. Existing guidelines for the design of extended end-plate link-column joints are modified to account for the variable shear force and moment associated with links of different lengths. Key words: steel, frame, eccentric, braced, bolted, end plate, link, connection.


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